I need to add finger rig to a model that is already rigged
I Googled further > found that I can select the main rig/metarig > go to Edit Mode > Go to Object Data > scroll to Rigify Buttons > Add two palms bones and the 10 fingers (by selecting each and clicking Add Sample) > scale them and link the joints respectively after. Doing this now and expect it will be all I needed. Just wished I could mirror and thus cut the work in half :)